Strange feeling in forearm hours after general anesthesia. Is this normal?

Positioning. Unclear what is happening, your discomfort could be related to your surgery, positioning, iv, phlebitis and other causes. Talk to your surgeon.
Maybe. There are several possibilities for this. This could be the hand in which you had your iv, in which case cold fluid was run through the vessels which can sometimes give strange tingly feelings in arm. The other possibility is a pressure injury. When you are asleep you cannot move to get pressure off some nerves, this can result in a numbness or tingling after surgery. It usually goes away quickly.
Not if persistent. If this lasts more than 1 day, contact the anesthesiologist and have it evaluated.